Different rotorcraft surfaces experience different levels of vibration. For example, a transmission of a rotorcraft experiences periodic vibration due to the rotation of the rotor, while a fuselage of the rotorcraft experiences relatively lesser vibration. A vibration isolation system is used in rotorcrafts such as helicopters and tiltrotors to dampen or isolate vibrations between two surfaces of the rotorcraft. For example, a vibration isolation system dampens or isolates periodic vibration of the transmission. A vibration isolation system sometimes includes an isolator on the rotorcraft transmission and an accumulator attached to the isolator. An isolator, for example, a liquid inertia vibration elimination (LIVE) unit, reduces or cancels transmissibility of vibration from one surface of a rotorcraft to another surface of the rotorcraft.